1. Field of the Invention
The invention relates generally to a device for conducting an adsorption/desorption temperature swing process, and more particularly to such a device that uses dry steam for purging a reactor during the desorption step.
2. Description of the Related Art
Temperature swing reactors are known in the art. During a temperature swing process a first part of the process is conducted at a first temperature, T1, and a second part of the process is conducted at a second temperature, T2. After completion of the second part of the process the temperature is swung back to T1, and the cycle recommences.
Temperature swing reactors can be used, for example, for adsorption/desorption processes, wherein the desorption temperature T2 generally is higher than the adsorption temperature, T1. It may be desirable to aid the desorption process by purging the reactor with an inert gas. Dry steam is often the preferred inert gas for this purging operation, because it can readily be produced on site, and is generally far less expensive than alternative inert gases, such as nitrogen or helium. In addition, water vapor can be easily separated from the desorbing gas by selective condensation.
Our co-pending patent application, filed on the same day as the instant application, entitled “Materials and Process for Reversible Adsorption of Carbon Dioxide”, which is hereby incorporated by reference in its entirety, discloses adsorbent materials from which carbon dioxide can be desorbed at least in part at temperatures below 100° C. It would be desirable to use an inert purging gas during the carbon dioxide desorption step of the process. However, conventional steam generation processes do not produce dry steam at temperatures below 100° C.
Thus, there is a particular need for a temperature swing reactor in which at least part of the desorption step is conducted at a temperature below 100° C., and in which dry steam can be used as a purging gas even at temperatures below 100° C.